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5 <TITLE>wxWidgets FAQ: General</TITLE>
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16 <b>wxWidgets FAQ: General</b>
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21
22 <P>
23
24 See also <a href="faq.htm">top-level FAQ page</a>.
25 <hr>
26 <h3>List of questions in this category</h3>
27 <ul>
28 <li><a href="#whatis">What is wxWidgets?</a></li>
29 <li><a href="#licence">Can I use wxWidgets for both proprietary projects, and GPL&#39;ed projects?</a></li>
30 <li><a href="#support">Is there support?</a></li>
31 <li><a href="#users">Who uses wxWidgets?</a></li>
32 <li><a href="#platforms">What platforms are supported by wxWidgets?</a></li>
33 <li><a href="#specific">How does wxWidgets support platform-specific features?</a></li>
34 <li><a href="#stl">Does wxWidgets use STL? or the standard string class?</a></li>
35 <li><a href="#richedit">Is there a rich edit/markup widget for wxWidgets?</a></ li>
36 <li><a href="#exceptions">How to use C++ exceptions with wxWidgets?</a></ li>
37 <li><a href="#dev">How is wxWidgets being developed?</a></li>
38 <li><a href="#distrib">How is wxWidgets distributed?</a></li>
39 <!--
40 <li><a href="#future">What are the plans for the future?</a></li>
41 -->
42 <li><a href="#base">What is wxBase?</a></li>
43 <li><a href="#univ">What is wxUniversal?</a></li>
44 <li><a href="#jave">What about Java?</a></li>
45 <li><a href="#dotnet">What about .NET/Mono?</a></li>
46 <li><a href="#help">How can I help the project?</a></li>
47 <li><a href="#newport">How do I start a new port?</a></li>
48 </ul>
49 <hr>
50
51 <H3><a name="whatis">What is wxWidgets?</a></H3>
52
53 wxWidgets is a class library that allows you to compile graphical C++ programs on a range of
54 different platforms. wxWidgets defines a common API across platforms, but uses the native graphical user interface (GUI) on each platform,
55 so your program will take on the native &#39;look and feel&#39; that users are familiar with.<P>
56
57 Although GUI applications are mostly built programmatically, there are several dialog editors to help
58 build attractive dialogs and panels. Robert Roebling&#39;s <a href="http://www.roebling.com">wxDesigner</a>
59 and Anthemion Software&#39;s <a href="http://www.anthemion.co.uk/dialogblocks/" target=_new>DialogBlocks</a>
60 are two commercial examples, but there are others: see the <a href="lnk_tool.htm">Useful Tools</a> page.<P>
61
62 You don&#39;t have to use C++ to use wxWidgets: there is a <a href="http://wxpython.org">Python interface</a> for wxWidgets,
63 and also a <a href="http://wxperl.sourceforge.net" target=_top>Perl interface</a>.
64 <P>
65
66 <h3><a name="licence">Can I use wxWidgets for both proprietary (commercial) projects, and GPL&#39;ed projects?</a></h3>
67
68 Yes. Please see the <a href="newlicen.htm">licence</a> for details, but basically
69 you can distribute proprietary binaries without distributing any source code, and neither will wxWidgets
70 conflict with GPL code you may be using or developing with it.
71 <P>
72 The conditions for using wxWidgets are the same whether you are a personal, academic
73 or commercial developer.
74 <P>
75
76 <h3><a name="support">Is there support?</a></h3>
77
78 No official support, but the mailing list is very helpful and some people say that
79 wxWidgets support is better than for much commercial software. The developers are
80 keen to fix bugs as soon as possible, though obviously there are no guarantees.
81 <P>
82
83 <H3><a name="users">Who uses wxWidgets?</a></H3>
84
85 Many organisations - commercial, government, and academic - across the
86 world. It&#39;s impossible to estimate the true number of users, since
87 wxWidgets is obtained by many different means, and we cannot monitor
88 distribution. The mailing list contains around 300-400 entries which is
89 quite large for a list of this type.<P>
90
91 See <a href="users.htm">Users</a> for a list of some users and their applications, and
92 also <A href="feedback.htm">Feedback</a> for comments.<P>
93 Our highest-profile user yet is industry veteran and Lotus Corp. founder Mitch Kapor
94 and his <a href="http://www.osafoundation.org" target=_new>Open Source Applications Foundation</a>.
95 <P>
96
97 <H3><a name="platforms">What platforms are supported by wxWidgets?</a></H3>
98
99 <ul>
100 <li>Windows 3.1, Windows 95/98, Windows NT, Windows 2000, Windows ME.
101 <li>Linux and other Unix platforms with GTK+.
102 <li>Unix with Motif or the free Motif clone Lesstif.
103 <li>Mac OS.
104 <li>Embedded platforms are being investigated. See the <a href="wxuniv.htm">wxUniversal</a> project.
105 <li>An OS/2 port is in progress, and you can also compile wxWidgets for GTK+ or Motif
106 on OS/2.
107 </ul>
108 <P>
109
110 <H3><a name="specific">How does wxWidgets support platform-specific
111 features?</a></H3>
112
113 This is a hotly-debated topic amongst the developers. My own philosophy
114 is to make wxWidgets as platform-independent as possible, but allow in a
115 few classes (functions, window styles) that are platform-specific.
116 For example, Windows metafiles and Windows 95 taskbar icons have
117 their own classes on Windows, but nowhere else. Because these classes
118 are provided and are wxWidgets-compatible, it doesn&#39;t take much
119 coding effort for an application programmer to add support for
120 some functionality that the user on a particular platform might otherwise
121 miss. Also, some classes that started off as platform-specific, such
122 as the MDI classes, have been emulated on other platforms. I can imagine
123 that even wxTaskBarIcon may be implemented for Unix desktops one day.
124 <P>
125
126 In other words, wxWidgets is not a &#39;lowest common denominator&#39; approach,
127 but it will still be possible to write portable programs using the
128 core API. Forbidding some platform-specific classes would be a stupid
129 approach that would alienate many potential users, and encourage
130 the perception that toolkits such as wxWidgets are not up to the demands
131 of today&#39;s sophisticated applications.<P>
132
133 Currently resources such as bitmaps and icons are handled in a platform-specific
134 way, but it is hoped to reduce this dependence in due course.<P>
135
136 Another reason why wxWidgets is not a &#39;lowest common denominator&#39; toolkit is that
137 some functionality missing on some platform has been provided using generic,
138 platform-independent code, such as the wxTreeCtrl and wxListCtrl classes.<P>
139
140 <H3><a name="stl">Does wxWidgets use STL? or the standard string class?</a></H3>
141
142 No. This is a much-discussed topic that has (many times) ended with the conclusion that it is in
143 wxWidgets&#39; best interests to avoid use of templates. Not all compilers can handle
144 templates adequately so it would dramatically reduce the number of compilers
145 and platforms that could be supported. It would also be undesirable to make
146 wxWidgets dependent on another large library that may have to be downloaded and installed.
147 In addition, use of templates can lead to executable bloat, which is something
148 wxWidgets is strenuously trying to avoid.<P>
149
150 The standard C++ string class is not used, again because it is not available to all compilers,
151 and it is not necessarily a very efficient implementation. Also, we retain more flexibility
152 by being able to modify our own string class. Some compatibility with the string class
153 has been built into wxString.<P>
154
155 There is nothing to stop an application using templates or the string class for its own
156 purposes. With wxWidgets debugging options on, you may find you get errors when including
157 STL headers. You can work around it either by switching off memory checking,
158 or by adding this to a header before you include any STL files:<P>
159
160 <PRE>
161 &#35;ifdef new
162 &#35;undef new
163 &#35;endif
164 </PRE>
165
166 <P>
167
168
169 <H3><a name="richedit">Is there a rich edit/markup widget for wxWidgets?</a></H3>
170
171 These are the possibilities so far:<P>
172
173 <ul>
174 <li>See <a href="http://www.scintilla.org" target=_top>www.scintilla.org</a> for
175 a very nice syntax-highlighting editor widget. Robin Dunn has written a wxWidgets wrapper
176 for this widget, available in the wxWidgets distribution under contrib/src/stc.
177 <li>If you only need to display marked-up information, rather than edit it,
178 then wxHTML will suit your needs. wxHTML is built into wxWidgets - please see the reference
179 manual for details, and samples/html.
180 <li>There are rich edit widgets in both WIN32 and GTK+, but there is currently
181 no wxWidgets wrapper for these (but text attribute functions are being added in the wxWidgets 2.3.x series).
182 </ul>
183
184 <P>
185
186 <h3><a name="exceptions">How to use C++ exceptions with wxWidgets?</a></h3>
187
188 wxWidgets library itself is unfortunately <i>not</i> exception-safe (as its
189 initial version predates, by far, the addition of the exceptions to the C++
190 language). However you can still use the exceptions in your own code and use
191 the other libraries using the exceptions for the error reporting together with
192 wxWidgets.
193
194 <p>
195 There are a few issues to keep in mind, though:
196 <ul>
197 <li>You shouldn&#39;t let the exceptions propagate through wxWidgets code,
198 in particular you should always catch the exceptions thrown by the
199 functions called from an event handler in the handler itself and not
200 let them propagate upwards to wxWidgets.
201
202 <li>You may need to ensure that the compiler support for the exceptions is
203 enabled as, considering that wxWidgets itself doesn&#39;t use the
204 exceptions and turning their support on results in the library size
205 augmentation of 10% to 20%, it is turned off by default for a few
206 compilers. Moreover, for gcc (or at least its mingw version) you must
207 also turn on the RTTI support to be able to use the exceptions, so you
208 should use <tt>--disable-no_rtti --disable-no_exceptions</tt> options
209 when configuring the library (attention to the double negation).
210 </ul>
211
212 <p>
213
214 <H3><a name="dev">How is wxWidgets being developed?</a></H3>
215
216 We are using the <a href="cvs.htm">CVS</a> system to develop and maintain wxWidgets. This allows
217 us to make alterations and upload them instantly to the server, from
218 which others can update their source.<P>
219
220 To build source from CVS, see the file BuildCVS.txt in the top-level wxWidgets distribution
221 directory.<P>
222
223 <H3><a name="distrib">How is wxWidgets distributed?</a></H3>
224
225 By ftp, and via the <a href="cdrom2.htm">wxWidgets CD-ROM</a>.
226 <P>
227 If you are feeling adventurous, you may also check out the sources directly
228 from <a href="cvs.htm">cvs</a>.
229 <p>
230
231 <!--
232 <H3><a name="future">What are the plans for the future?</a></H3>
233
234 TODO
235
236 <p>
237
238 -->
239
240 <h3><a name="base">What is wxBase?</a></h3>
241
242 wxBase is a subset of wxWidgets comprised by the non-GUI classes. It includes
243 wxWidgets container and primitive data type classes (including wxString,
244 wxDateTime and so on) and also useful wrappers for the operating system objects
245 such as files, processes, threads, sockets and so on. With very minor
246 exceptions wxBase may be used in exactly the same way as wxWidgets but it
247 doesn&#39;t require a GUI to run and so is ideal for creating console mode
248 utilities or server programs. It is also possible to create a program which can
249 be compiled either as a console application (using wxBase) or a GUI one (using
250 a full featured wxWidgets port).
251
252 <H3><a name="univ">What is wxUniversal?</a></H3>
253
254 The main difference between wxUniversal-based ports (such as wxX11, wxMGL) and other ports (such as wxMSW, wxGTK+, wxMac)
255 is that wxUniversal implements all controls (or widgets) in
256 wxWidgets itself thus allowing to have much more flexibility (for example, support for
257 themes even under MS Windows). It also means that it is now much easier to
258 port wxWidgets to a new platform as only the low-level classes must be ported
259 which make for a small part of the library.
260 <p>
261 You may find more about wxUniversal <a href=wxuniv.htm>here</a>.
262
263 <H3><a name="jave">What about Java?</a></H3>
264
265 The Java honeymoon period is over :-) and people are realising that it cannot
266 meet all their cross-platform development needs. We don&#39;t anticipate a major threat
267 from Java, and the level of interest in wxWidgets is as high as ever.<P>
268
269 <H3><a name="dotnet">What about .NET/Mono?</a></H3>
270
271 Microsoft is spending a lot on promoting the .NET initiative, which
272 is a set of languages, APIs and web service components for Windows.
273 Ximian has started an open source version of .NET, mostly for Linux.
274 C&#35; is Microsoft&#39;s alternative to Java, supporting &#39;managed code&#39;,
275 garbage collection and various other Java-like language features.<P>
276
277 Although this may be attractive to some developers, there
278 is a variety of reasons why the .NET/Mono combination is unlikely
279 to make wxWidgets redundant. Please note that the following comments
280 are Julian Smart&#39;s opinions.<P>
281
282 <ol>
283 <li>Not everyone wants or needs net services.
284 <li>C++ will be used for a long time to come; compared with C++, C&#35; is a recent development and its future is not certain.
285 <li>Mono Forms may only target Winelib (at least to begin with), so the end result is not as native as
286 wxWidgets (I&#39;m aware there is GTK&#35; for use with the C&#35; language).
287 <li>C&#35; is usually byte-compiled and therefore slower. Plus, .NET adds a layer of overhead to the client computer
288 that wxWidgets does not require.
289 <li>Mono hasn&#39;t proven its long-term viability yet (it&#39;s a complex system of components); wxWidgets is ready now.
290 <li>You may not wish to buy into Microsoft marketing spin and APIs.
291 <li>Microsoft may at some point sue developers of non-Microsoft .NET implementations. After all,
292 platform-independence is not in Microsoft&#39;s interest.
293 <li>.NET might never be implemented on some platforms, especially Mac and embedded variants of Linux.
294 <li>wxPython and other language variants provide further reasons for wxWidgets to continue.
295 <li>The same issue exists for Qt: if Qt sales remain strong, it&#39;s a good indication that
296 the market for a C++-based approach is still there. (Either that, or everyone&#39;s turning to wxWidgets!)
297 </ol>
298
299 There is nothing to stop folk from developing a C&#35; version of the wxWidgets API;
300 we already have bindings to Python, Perl, JavaScript, Lua, Basic, and Eiffel.
301 Update: a <a href="http://wxnet.sourceforge.net/" target=_new>wx.NET</a> project is now in progress.
302
303 <P>
304
305 <H3><a name="help">How can I help the project?</a></H3>
306
307 Please check out the <a href="http://www.wxwidgets.org/develop2.htm">Community</a> pages,
308 in particular the <a href="projects.htm">suggested projects</a>, and
309 mail the developers&#39; mailing list with your own suggestions.<P>
310
311 <H3><a name="newport">How do I start a new port?</a></H3>
312
313 Please subscribe to the wx-dev <a href="maillst2.htm">developers&#39; mailing list</a> and
314 ask if anyone else is interested in helping with the port, or
315 has specific suggestions. Also please read the <a href="standard.htm">coding standards</a>.
316
317 <P>
318 Each port consists of a platform-specific part (e.g. src/msw, include/wx/msw),
319 a generic set of widgets and dialogs for when the port doesn&#39;t support
320 them natively (src/generic, include/wx/generic) and the common code
321 that all ports use (src/common, include/wx). By browsing the source
322 you should get a good idea of the general pattern.<P>
323
324 Take a port that most closely matches your port, and strip out
325 the implementation so you have a skeleton port that compiles. Ask on wx-dev
326 first for the wxStubs port - however, any such predefined skeleton
327 port may be out of date, so make a judgement on whether to use it.
328 Perhaps it will still save you time to clean up wxStubs, and
329 others may benefit from this too.<P>
330
331 You will need to define a symbol for the new port, e.g. __WXXBOX__.
332 Look at files such as wx/defs.h, wx/wxchar.h for areas where you&#39;ll
333 need to add to existing conditionals to set up wide character
334 support and other issues. If the GUI runs on a Unix variant,
335 define the __UNIX__ variable in your makefile.<P>
336
337 Then you can start implementing the port, starting with
338 wxWindow, wxTopLevelWindow, wxFrame, wxDialog so you
339 can get the minimal sample running as soon as possible.<P>
340
341 If GDI objects (wxPen, wxBrush, etc.) are not concepts in your
342 native GUI, you may wish to use very generic versions of
343 some of these - see the wxX11 port.<P>
344
345 Consider using the wxUniversal widget set as a quick way
346 to implement wxWidgets on your platform. You only need
347 to define some basic classes such as device contexts,
348 wxWindow, wxTopLevelWindow, GDI objects etc. and
349 the actual widgets will be drawn for you. See wxX11,
350 wxMGL, and wxMSW/Univ for sample wxUniversal ports.<P>
351
352 To begin with, you can use whatever makefiles or project
353 files work for you. Look at existing makefiles to see what
354 generic/common/Unix files need to be included. Later, you&#39;ll want to integrate support
355 for your port into configure (Unix-like systems and gcc under Windows),
356 and bakefile (for other makefiles on Windows).<P>
357
358 Submit your port as patches via SourceForge; you might
359 wish to separate it into one patch that touches common headers
360 and source files, and another containing the port-specific code, to make
361 it much easier for us to review and apply the patches.<P>
362
363 Good luck!
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